Crystal structures are described by phase and magnitude components. The phase indicates the location of matter within the crystal, and the magnitude tells how much matter there is. Usual methods of structure determination are indirect, relying exclusively on magnitude. Structures are deduced by iteratively refining computational models and matching them to experimental observations. Now, Philip N. H. Nakashima, Alexander F. Moodie, and Joanne Etheridge of Monash University, in Melbourne, Australia, . . .